Organo-phosphono-amine oxides



United States Patent 3,429,914 ORGANO-PHOSPHONO-AMINE OXIDES Marvin M.Crutchfield and Riyad R. Irani, St. Louis, Mo.,

assignors to Monsanto Company, St. Louis, Mo., a

corporation of Delaware No Drawing. Filed Sept. 3, 1964, Ser. No.394,350 US. Cl. 260-5025 4 Claims Int. Cl. C07f 9/38 ABSTRACT OF THEDISCLOSURE Organo-phosphonoamine oxide compounds are described includingacids having the formula wherein R and R are each selected from thegroup consisting of alkyl, aryl, alkaryl, aralkyl, alicyclic,hydroxysubstituted derivatives of the foregoing,

XOOH

and

wherein X and Y are each selected from the group consisting of hydrogenand lower alkyl, m is an integer from 1 to 10, p is an integer O to 1,and R and R each do not contain over 6 nitrogen atoms; and salts thereofsuch as salts of alkali metals, alkaline earth metals, aluminum,ammonium and amines.

This invention relates to organo-phosphono-amine oxides and processesfor preparing the same.

An object of this invention is to provide new and usefulorgano-phosphono-amine oxide compounds containing at least one group permolecule.

A further object of this invention is to provide new and useful acidsand salts of organo-phosphono-amine oxide compounds containing at leastone group consisting of acids having the general formula 7 3,429,914Patented Feb. 25, 1969 wherein: X and Y are each selected from the groupconsisting of hydrogen and lower alkyl (1-6 carbon atoms) and R and Rare each selected from the group consisting of alkyl, aryl, alkaryl,aralkyl, alicyclic, hydroxy-substituted derivatives of the foregoing,

X A l 1 r Y m R2 wherein: m is an integer from 1 to 10, A when presentis oxygen, and R and R does not contain over 6 nitrogen atoms; and saltsthereof selected from the group consisting of alkali metals, alkalineearth metals, aluminum, ammonium and amines.

When the symbols R and R represent groups containing carbon chains, suchas alkyl groups or groups containing alkyl moieties, i.e., aralkylgroups and the like, such carbon chains may be of a straight chainstructure or a branched chain structure. Additionally, the carbon chainsshould preferably contain less than about 20 carbon atoms. For thesymbols R and R when representing alicyclic groups such are preferably 5and 6 membered mono-cyclic alicyclic groups. When the symbols R and Rrepresent aryl groups and groups containing aryl moieties, i.e., alkarylgroups and the like, such groups are preferably mono-cyclic. Althoughthe carbon atoms of the alkyl, alicyclic, aryl, alkaryl, aralkyl groupsmay contain many hydroxy substituents, for example, at least one hydroxysubstituent per carbon atom in the group, it is preferred that suchgroups contain less than 1 hydroxy substituent per carbon atom in thegroup and more preferred for groups containing many carbon atoms, i.e.,about 4 carbon atoms or more, less than about 3 hydroxy substituents pergroup. For most end use applications the compounds of the instantinvention should preferably contain not more than about 25 carbon atomsassociated with R and R and there are few, if any, end uses in which theforegoing groups contain more than a total of 50 carbon atoms.

These compounds can be characterized quite generally as having at leastone and linkages in their molecules and are generically described in thespecification by the general term organo-phosphonoamine oxides.

In general, the organo-phosphono-amine oxides can be prepared by theprocess of oxidizing organo-phosphonoamines with a suitable oxidizingagent. Suitable oxidizing agents are, in general, any oxidizing agentcontaining an 0-0 linkage (peroxide compound) and having an oxidizingaction. In particular, suitable oxidizing agent include hydrogenperoxide, substituted peroxides and addition compounds of hydrogenperoxide, such as the peroxide of sodium and the super oxide ofpotassium, urea percompounds, perborates, persulfates and the peracidssuch as persulfuric acid, peracetic acid, peroxy monophosphorlc acid andthe like as well as their water-soluble salt compounds such as sodium,potassium, ammonium and organic amine salts, with hydrogen peroxidebeing particularly preferred. In general, the oxidation process can becarried out in an aqueous medium, i.e., an aqueous solvent orsuspension, as well as in organic solvents such as alcohols, benzene andthe like. Although excessive temperature conditions should be avoideddue to the possible degradation of either the organo-phosphono-amine ororgano-phosphono-amine oxide and/or the dangerous tendency of theoxidizing agent to decompose rapidly, ordinary or elevated temperaturesi.e., from about to 100 C. and even higher in some cases, can be usedwith temperatures from about 20 to 85 C. being preferred. Concentrationsof the oxidizing agent in the reaction medium can vary considerably,however, it is preferred to use concentrations above about by weight ofthe reaction medium with concentrations from about to 50% by weightbeing particularly preferred. It should be noted that with compoundscontaining more than 1 nitrogen atom it is possible by varying thereaction conditions to either oxidize substantially all of the nitrogenatoms or only one nitrogen atom to the amine oxide form.

The salts of the organo-phosphono-amine oxides can be prepared byneutralization of the acids with a stoichiometric amount of a base orsalt that contains essentially the desired cation or by conversion ofthe organo-phosphono-amine to a salt form prior to its oxidation to theamine oxide. Bases or salts of volatile acids such as those containingan alkali metal, alkaline earth metal, aluminium, ammonia and amines areespecially suited. For example, to make a sodium salt, one of the freeacids of the organo-phosphono-arnine oxides can be neutralized with astoichiometric amount of a base containing the sodium cation, such asNaOH, Na CO and the like.

For the foregoing methods of preparation reaction conditions such astemperatures, pH and time for reaction can be varied with the optimumconditions for the reactions readily ascertained by those skilled in theart. It has been found that a convenient method for determiningfavorable conditions in individual cases is provided by the H and Pnuclear magnetic resonance (NMR) signals which can be obtained from asmall sample i.e., about 0.5 ml., of the reaction mixture. The formationof the semi-polar bond between nitrogen and oxygen as the reactionproceeds produces a change in the local magnetic environments of thehydrogen atoms on the carbon atoms adjacent to the N O group as well asof the phosphorus atoms. As a result the NMR signals which are observedfor these atoms in the starting amine slowly disappear as the reactionproceeds, while simultaneously new and different signals are observed toappear for these atoms in the amine oxide reaction product. Observationof these signals can also serve to warn of extreme conditions ofexcessive time and/or temperature which can lead to additional undesiredoxidation or even complete destruction of the product. Additionally, forstarting materials which are appreciably water-soluble, such astris'(dihydrogen phosphonomethyl)amine, N[CH 'PO H the reaction isconveniently carried out in aqueous solution with the formation ofwater-soluble products which can be isolated by the evaporation ofsolvent and excess peroxide either under vacuum, or at atmosphericpressure. For starting materials which are not readily soluble in water,such as decyl, bis(dihydrogen phosphonomethyl)amine, C H N[CH PO H useof an organic solvent or conversion of the phosphono acid group orgroups to a soluble salt form is preferred to increase the aqueoussolubility of the amine prior to reaction with the peroxide. Forstarting materials which are sparingly soluble in water or peroxidesolution and which form amine oxides which are appreciably more watersoluble, such as, tetrakis(dihydrogen phosphonomethyl)ethylene diamineorder to assist in teaching the methods of their preparation.

The organo-phosphono-amines useful as starting materials to prepare thecompounds of instant invention can be prepared by the reaction of anitrogenous matenal (ammonia, primary amines or secondary amines), acompound containing a carbonyl group (aldehyde or ketone) andorthophosphorous acid. Generally, by heating the mixture above about 50C. at a relatively low pH, preferably about 2 or below, the extent ofthe reaction is usually completed in a few hours. Another method is thehydrolysis of the esters of the organo-phosphono-amines withconcentrated HCl or HBr. Generally, by refluxing the ester and acid atreflux temperature for a period of a few hours is all that is requiredfor the hydrolysis.

In general, the organo-phosphono-amine oxides of the present inventionhave utility in practically all fields of organic chemistry whereintheir acidic or salt and/or amine oxide properties can be utilized.

In particular, the compounds of the instant invention can find utilityin such fields as sequestering or chelating agents, water-treatingagents, stabilizers for peroxy compounds, soap anti-oxidants, additivesin liquid soap, detergents and shampoos, agents for use in scouring woolcloth and cotton kier boiling, metal cleaning compositions, rubber andplastic compositions and polymerization processes, bottle washingcompositions, dairy cleaning compositions, agents for use in pulp andpaper processing, corrosion inhibitors, feed and vegetation supplements,herbicides, insecticides, metal treating compositions, electroplating,detergent builders or additives, lime soap dispersants, surfactants,film formers in hair sprays and soluble packages, dispersants for clays,drilling muds, paper pulps, inorganic and organic pigments, and cementslurries, bactericide potentiators, hair modifiers in shampoos,fertilizers, food and beverage acidulants, leavening agents, cheeseemulsifiers, modifying agents in evaporated and condensed milk, flameretardants in paints and plastics, oil additives, gasoline additives,dentrifice compositions and the like.

In particular, the acids and water-soluble salts of the tris (phosphonolower alkylidene)amine oxides were found to exhibit the property ofbeing etfective sequestering agents for metal ions in alkaline mediums.For example, the penta sodium salt of tris(dihydrogenphosphonomethyl)amine oxide was found to sequester Ca++ ions in alkalinemedia in over a mole per mole basis (Ca++ per sequestering agent). Theacid compounds are of the following formula:

wherein X and Y are each selected from the group consisting of hydrogenand lower alkyl (1-4 carbon atoms). Although any water-soluble salt canbe used, the preferred salts are the sodium salts and in particular thepenta sodium salts although other alkali metal salts, such as potassium,lithium and the like, as well as mixtures of the alkali metal salts maybe used.

In particular, the acids and water-soluble salts of the higher alkylbis(phosphono lower alkylidene)amine oxides were found to exhibit theproperty of being effective surfactants and lime soap dispersants. Theacid compounds are of the following formula:

wherein X and Y are each selected from the group consisting of hydrogenand lower alkyl (1-4 carbon atoms) and R is an alkyl group containingfrom 4 to 20 carbon atoms. Although any water-soluble salt can be used,the preferred salts are the sodium salts and in particular the trisodiumsalts although other alkali metal salts. such as potassium, lithium andthe like, as well as mixtures of the alkali metal salts may be used.

The following examples are presented to illustrate the invention, withparts and percentages by weight being used in the examples unlessotherwise indicated.

EXAMPLE 1 In a suitable reaction vessel about 150 grams of tris(dihydrogen phosphono methyl)amine is added to about 169 ml. of 30% H 0and the reaction mixture is stirred for about 12 hours at about 35 C.The reaction product is dried at about 25 C. under a stream of dry air.The product, after being washed with methanol and air dried, yieldsabout 119' grams of tris(dihydrogenphosphono mcthyl)amine oxide, ON(CHPO H Elemental analysis yields the following results. Found: C, 11.39%;'H, 3.81%; P, 29.39%; N, 4.34%; O, 51.07%. Calculated: C, 11.44%; H,3.84%; P, 29.50%; N, 4.45%; O, 50.78%. The equivalent weight of thisproduct, by titration, is found to be about 317 which compares favorablywith the calculated value of about 315. The P and H NMR spectra areconsistent with the formation of an bond. The acid tritration curveindicates that the acid dissociation constants of the product difierfrom those of the starting amine.

The sodium salt, bis(disodium phosphonomethyl) (monosodium hydrogenphosphonomethyl)amine oxide ON (CH PO NaH) (CH PO Na 2 is prepared bydissolving about 31.5 grams of the free acid obtained as in this examplein about 50 grams of H 0 and neutralizing by the addition of about 40.0grams of 50% NaOH. The aqueous solution is evaporated to dryness undervacuum below 50 C.

The monocalcium salt, calcium tetrahydrogen tri(phosphonomethyl)amineoxide is prepared by dissolving about 31.5 grams of the free acidobtained as in this example in about 100 grams of water andprecipitating by the slow addition of about 22.2 grams of 50% CaClsolution. The calcium salt is filtered oif, washed and air dried.

EXAMPLE 2 In a suitable reaction vessel about 22 grams of methyl, bis(dihydrogen phosphonomethyl) amine is added to about 34 grams of 30% H 0and stirred for about 1 to 2 hours at about 90 C. Analysis of the P NMRspectrum of the product, a viscous syrup, after being dried byevaporation under a stream of dry air at 25 C., indicates methyl,bis(dihydrogen phosphonomethyl) amine oxide, CHgN (O) (CH PO H Thepotassium salt, methyl, (dipotassium phosphonomethyl) (monopotassiumhydrogen phosphonomethyl) amine oxide is prepared by dissolving about21.9 grams of the free acid in about 33.6 grams of 50% KOH solution andevaporating the aqueous solution to dryness at about 50 C., undervacuum.

EXAMPLE 3 In a suitable reaction vessel about 31.3 grams of tris-(dihydrogen phosphono ethylidene)amine is added to about 22.3 grams of30% H 0 and the reaction mixture is stirred for about 20 hours at about40 C. Evaporation at about 25 C. under a stream of dry air yields theamine oxide, tris (dihydrogen phosphono ethylidene)- amine oxide, N(O)(CH CHPO I-I The diammonium salt, bis(monoammonium hydrogen phosphonoethylidene)(dihydrogen phosphono ethylidene)amine oxide ON (CH CHPONH H(CH CHPO H is prepared by dissolving about 10 grams of the free acid inabout grams of water, followed by the addition of concentrated NHsolution, until the pH of the mixture is about 3.5. The ammonium salt isthen obtained by evaporation of the solvent under vacuum at about C.

EXAMPLE 4 In a suitable reaction vessel about 13.9 grams of dirnethyl,(dihydrogen phosphonomethyl)amine is added to about 22.3 grams of H 0and the reaction mixture is stirred for about 48 hours at about 60 C. Hand P NMR spectra of the reaction mixture show reaction to form theamine oxide, dimethyl (dihydrogen phosphonomethyl)amine oxide,

Addition of excess of a saturated solution of aluminum nitrate, Al(NOprecipitates as a gelatinous solid In a suitable reaction vessel about29.3 grams of dodecyl, methyl(dihydrogen phosphono methyl)amine isneutralized with about 60 grams of 10% NaOH and about 22.3 grams of 30%H 0 is added. The reaction mixture is stirred for about hours at aboutC. Excess hydrogen peroxide is destroyed at about 25 C. by the additionof a trace of catalase enzyme and the reaction mixture poured into coldexcess concentrated HCl. The free acid, dodecyl, mehtyl (dihydrogenphosphonomethyl)-amine oxide,

precipitates and is separated by filtration. The solid product is washedwith acetone and air dried.

A portion of the above acid is converted to the ammonium salt bydissolving in excess concentrated NH solution and evaporating thedryness of 0 C. under vacuum. The product is dodecyl,methyl(monoammonium hydrogen phosphonomethyl)amine oxide.

EXAMPLE 6 Into a suitable reaction vessel about 100 grams of decyl,bis(dihydrogen phosphonomethyl)amine, about 47.5 grams of 50% NaOH andabout 227 grams of H 0 are charged and heated to dissolve the acid. Tothis reaction mixture, about 39.5 grams of 50% H 0 are added and thisreaction mixture is heated to about C. for about 10 hours. After coolingthe solution to about 25 C., about 500 mg. of catalase is added todestroy the excess peroxide by standing for about 24 hours. A portion ofthis solution is added to excess concentrated HCl with a precipitateforming which is filtered, washed with acetone, and air dried. Analysisof the P NMR spectra of the product indicates decyl, bis(dihydrogenphosphonomethyDamine oxide, C10H21N(O) (CH2PO3H2)2.

A portion of the acid product solution obtained as in this example isneutralized with 50% NaOH solution to a pH of about 10.5 and afterdrying by evaporation for several days at about 25 C. yields the sodiumsalt, decyl, (disodium phosphonomethyl) (monosodium hydrogenphosphonomethyl)amine oxide H 0 are charged and heated to dissolve theacid. To this reaction mixture, about 19.4 grams of 50% H 0 are addedand this reaction mixture is heated to about 60 C. for about 24 hours.After cooling the solution to about 25 0., about 500 mg. of catalaseenzyme is added to destroy the excess peroxide. A portion of thissolution is added to excess concentrated HCl with a precipitate formingwhich is filtered, washed with acetone and air dried. The precipitatedproduct is tetradecyl, bis- (dihydrogen phosphonomethyl)amine oxideEXAMPLE 8 In a suitable reaction vessel about 43.6 grams of tetrakis(dihydrogen phosphonomethyl)ethylene diamine is slurried in about 68grams of 30% H and stirred for about 24 hours at about 35 C. Thereaction product, after being evaporated in air to remove excess solventyields about 46 grams of solid material. Analysis of the P NMR spectraof the product indicates tetrakis (dihydrogen phosphonomethyl) ethylenediamine, N,N'- dioxide 0 o (HzOsPcHzh 'cHzCHz KCHzPoaHz)2 A hexasodiumsalt is prepared by dissolving about 23 grams of the free acid in about60 grams of 20% NaOH solution, followed by evaporation to dryness undervacuum at about 50 C.

A diamine salt is prepared by adding about 23 grams of the free acid toabout 36.5 grams of a 20% solution of an n-butyl amine in water. Onevaporation to dryness under vacuum 2 21 3 21212 2 2 2)2 s is obtainedas a sticky solid.

EXAMPLE 9 In a suitable reaction vessel about 24.9 grams of ethanol bis(dihydrogen phosphonomethyl)amine is added to about 22.3 grams of 30% H0 and stirred for about 24 hours at about 60 C. Evaporation at about 25C.

under vacuum yields the amine oxide, ethanol bis(dihydrogenphosphonomethyl)amine oxide A mono-calcium salt is prepared bydissolving about 13 grams of the free acid in about 26 grams of H 0,followed by the slow addition of about 27.5 grams of 20% CaCl solution.Solid (HOC HQNQO) [CH PO(OH) [OH PO Ca] precipitates, is filtered 01f,washed with water and dried.

EXAMPLE In a suitable reaction vessel about 35.1 grams of ethanol,tetradecyl(dihydrogen phosphonomethyl)amine is neutralized with about12.0 grams of 50% NaOH solution plus sufiicient water to solubilize.About 22.3 grams of 30% H 0 is added and the reaction mixture is stirredfor about 48 hours at about 60 C. Excess H 0 is destroyed and thereaction mixture poured into cold concentrated HCl. The free acid,ethanol, tetradecyl, (dihydrogen phosphonomethyl)amine oxide after beingair dried at about 25 C. to remove excess solvent yields about 47 gramsof solid tetra'kis (dihydrogen phosphonomethyl)trimethylene diamine,N,N'-dioxide EXAMPLE 12 In a suitable reaction vessel about 57.3 gramsof pentakis (dihydrogen phosphonomethyl)diethylene triamine is slurriedin about 68 grams of 30% H 0 and stirred for about 48 hours at 35 C. Thereaction product, after evaporation of excess solvent, yields penta kis(dihydrogen phosphonomethyl)diethylene triamine N,N,N"- trioxide o 0 0(H2O3P CH2) zIECHzCHZIlKCHzP 0 112) CHzCHfl HCHzP 03112):

EXAMPLE 13 In a suitable reaction vessel about 46 grams ofbis(dihydrogen phosphonomethyl), bis(dihydrogen phosphonoisopropylidene)ethylene diamine is slurried in about 68 grams of 30% H 0and stirred for about 48 hours at about 35 C. The reaction product isthen evaporated to dryness at about 25 C. under vacuum to yield solidbis- (dihydrogen phosphonomethyl), bis(dihydrogenisopropylidene)ethylene diamine, N,N-dioxide EXAMPLE 14 In a suitablereaction vessel about 34.6 grams of nhexyl, bis(dihydrogen phosphonoisopropylidene)amine is dissolved in about grams of 10% NaOH and about22.3 grams of 30% H 0 is added thereto. The solution is heated at about60 C. for about 12 hours. Excess solvent is removed by vacuumevaporation to yield the salt 0 (CQHICOIGIZC (CH3)2P OaNazHC (CHQ PogHNal EXAMPLE 15 In a suitable reaction vessel about 28.1 grams ofphenyl bis(dihydrogen phosphonomethyl)amine is slurried with about 22.3grams of 30% H 0 and heated at about 50 C. for about 24 hours withefficient stirring. Excess water and peroxide are removed by vacuumevaporation to yield phenyl bis(dihydrogen phosphonomethyl)amine oxide TCuHsNI Z :112]:

EXAMPLE 16 In a suitable reaction vessel about 28.7 grams of cyclohexyl,bis(dihydrogen phosphonomethyl)amine is slurried with about 34 grams of30% H 0 and heated to about 50 C. for about 24 hours with eflicientstirring. Vacuum evaporation of excess water and H 0 yield cyclohexyl,bis(dihydrogen phosphonomethyl)amine oxide Other compounds of theinstant invention which can be prepared according to the procedures asillustrated by the foregoing examples include the following:

( 1) N (2 hydroxyethyl)tris(dihydrogen phosphono methyl)ethylene diamineN,N'-dioxide 2 t [CH PO(OH)rllCHzCHzOHlNtCHzlsNiCHaP0(011)212 11 12 (33)hexylphenyl bis(dihydrogen phosphonomethyl) 2. A higher alkylbis(phosphono lower alkylidene) amine oxide amine oxide having theformula 2 o x OH CeHm-CqHdHCHzP OaHz]; :l

I (34) xylyl bis(dihydrogen phosphonomethyl)amine ox- Y 0H ide wherem Xand Y are each selected from the group con- 0 sisting of hydrogen andlower alkyl and R is an alkyl (CHMCBHSITHCHZP oaHzh group contalmng from4 to 20 carbon atoms.

3. An alkali metal salt compound of a higher alkyl bis- Other bases orsalts which can be reacted with the (Phosphono lower a1kyfidene)amineoxide havmg the free acids to produce salt compounds of the instantinformula vention according to the procedures as illustrated by the 0 X0 OZ foregoing examples include the inorganic alkali metal, E T;alkaline earth metal and aluminum salts, oxides and hyi droxides, suchas, NaCl, NaNO Na O, Na CO 2 co KOH, 0 c co KNOs LiOH Licl wherein X andY are each selected from the group con- LiNO Li CO CsOH, CsCl, CsNO CsCO c c slsting of hydrogen and lower alkyl and R is an alkyl C20, c coMaclz, M8003, Bacoa Baclz Ba(OH)2, group contalmng from 4 to 2( carbonatoms, and Z is 5 31-012 Sl-(QH)2 A](OH)3, A1203, A1(NO3)3, and selectedfrom the group consisting of hydrogen and alkali amines, particularlylow molecular weight amines, i.e., metab Wlth at least'one grouprepresented y Z bemg having a molecular weight below about 300, and morealkah metalparticularly the alkyl amines, alkylene amines and alkanolDecyl blswlhydrogen Phosphono methynamme amines containing not more than2 amine groups, such as, ethyl amine, diethylamine, propyl amine,propylene References Cited diamine, hexyl amine, 2-ethyl hexyl amine,N-butyl etha- UNITED STATES PATENTS nol amine, triethanol amine and thelike. 2 169 976 8/1939 Guenther et aL what F 2,599,807 6/1952Bersworth. 1. A hlgher alkyl b1s(phosphon0 lower alkylidene) 2 635 1124/1953 Fields amine oxide selected from the group consisting of acids2673214 3/1954 Berswbrth et a1. havmg the immula 3,047,579 7/1962Witman.

3,053,633 9/1962 Dunlop et al. 3,234,140 2/1966 Irani 252-186 g I 1 /OH2,288,846 11/1966 Iraniet a1. RN|:( J-P OTHER REFERENCES Y 0H 2 Petrovet al.: Chem. Abst., vol, 54 (1960), col. 260.

LEON ZITVER, Primary Examiner.

wherein X and Y are each selected from the group con- EVANS AssistantExaminer sisting of hydrogen and lower alkyl and R is an alkyl U 5 C1 XRgroup containing from 4 to 20 carbon atoms, and the alkali metal saltsthereof. 210-38; 252117, 152; 260-448, 501.19, 501.2, 501.21

222 5 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3329,91 Dated Pebruarv 1969 Inventor) Marvin M. Cr'utchfield 8 Riyad R,Ipani It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

FColumn ll, lime l9 chemical terms reading "M Cl M CO should read M C1 MC0 SIGNED AND SEALED AUG 4 --I970 Edwmlnflacheizlr.

Attcsting Officer mm E. SGHUYLER, JR. Gomissiono'r of Patent:

